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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-02-02 to 1988-02-26
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study without GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Principles of method if other than guideline:
The selected method was the maximization test of Magnusson-Kligman (1969). J Invest Dermatol 52: 268-276.
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Study was performed before LLNA was formally validated and available as OECD guideline in 2002.

Test material

Constituent 1
Chemical structure
Reference substance name:
4-tert-butyltoluene
EC Number:
202-675-9
EC Name:
4-tert-butyltoluene
Cas Number:
98-51-1
Molecular formula:
C11H16
IUPAC Name:
1-tert-butyl-4-methylbenzene
Details on test material:
- Name of test material (as cited in study report): p-tert-butyltoluene
- Physical state: colourless liquid
- Analytical purity: 99.53%
- Impurities (identity and concentrations): no data
- Lot/batch No.: 2339/8608; date of manufacture: 1986-08-12
No further data

In vivo test system

Test animals

Species:
guinea pig
Strain:
Pirbright-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
female albino guinea pigs, Bor:DHPW
- Source: F. Winkelmann, D-4799 Borchen; Germany
- Age at study initiation: no data
- Weight at study initiation: mean body weights: 330.1 g (experimental group); 330.9 g (control group)
- Housing: 1 - 5 animals in Type IV Makrolon cages
- Diet (ad libitum): feed for guinea pigs, Ssniff Spezialfutter GmbH, D-4770 Soest
- Water (ad libitum): tap water
- Acclimation period: 4 - 8 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 21°C
- Humidity (%): 55 - 65%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: no data

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: Freund's Complete Adjuvant (FCA), maize germ oil, water
Concentration / amount:
20% (intracutaneous induction);
undiluted (epicutaneous induction);
50% (challenge)
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
other: Freund's Complete Adjuvant (FCA), maize germ oil, water
Concentration / amount:
20% (intracutaneous induction);
undiluted (epicutaneous induction);
50% (challenge)
No. of animals per dose:
20 females (test group);
10 females (control group)
Details on study design:
RANGE FINDING TESTS:
no data

MAIN STUDY
A. INDUCTION EXPOSURE

1. intracutaneous induction
A 4 x 6 cm area of skin on both shoulders is carefully shaved. 2 to 3 hours later, a total of 6 intracutaneous injections are administered symmetrically and simultaneously as follows, each on the right and left:
- 0.1 ml Freund's Complete Adjuvant (FCA) and water in the ratio 1 : 1
- 0.1 ml of test product 20 % in maize germ oil
- 0.1 ml of test product 20 % in a mixture of FCA and maize germ oil in the ratio 1 : 1.
The control animals receive the same number of intracutaneous injections in the same area of the back as follows:
- 0.1 ml of a mixture of FCA and water in the ratio 1 : 1
- 0 .1 ml maize germ oil
- 0.1 ml of a mixture of FCA and maize germ oil in the ratio 1 : 1.

2. epicutaneous induction
One week after the intracutaneous injections the patch test is carried out. The skin over the injection area is shaved, and 2 to 3 hours later, a 2 x 4 cm filter paper, impregnated with the undiluted test substance, is placed thereon and covered with a 6 x 6 cm adhesive tape (Leukoflex). The patch 40 is immobilised for 48 hours with an elastic dressing. The control animals receive a patch containing maize germ oil.

B. CHALLENGE EXPOSURE
The challenge exposure is effected two weeks later. The left flank of the guinea pigs is shaved. 2 to 3 hours later, a 2 x 2 cm filter paper is impregnated with the test substance 50 % in maize germ oil for each animal and placed on the left front flank. The patch is covered with a 6 x 6 cm adhesive tape (Leukoflex) and immobilised for 24 hours with an elastic dressing.
The control animals receive the same treatment.
The reaction is assessed 24 and 48 hours after removal of the elastic dressing. If necessary the skin is shaved 2 - 3 hours beforehand.

The reactions are evaluated in accordance with the following scheme:
No erythema: 0
Slight erythema: 1
Distinct and diffuse erythema: 2
Severe erythema and edema: 3

OTHER:
The animals were weighed before the start of the experiment and then once a week.
Challenge controls:
no data
Positive control substance(s):
not specified

Results and discussion

Positive control results:
no data

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50%
No. with + reactions:
1
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50%. No with. + reactions: 1.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

Sensitisation reactions:
Skin reactions were seen in 0/20 test animals and in 0/10 control animals at both the 24- and 48-hour reading.
 
General observations:
There were no general reactions during the investigation, and the treatment had no serious influence on the increase in body weight.
Local reactions were limited to irritation at the sites treated with FCA by intracutaneous injection and topical application; erythema, edema, slight necrosis, and eschar formation were recorded in both test and control animals.
At the sites treated with maize germ oil, slight erythema and edema was noted at the injection sites.
 
For details, see attached files.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
In the maximization test of Magnusson-Kligman, p-tert.-butyltoluene showed no sensitising effect on the skin of female guinea pigs.